Method of manufacturing insulators



July 28, 1931. OSBORNE 1,816,023

METHOD OF MANUFACTURING INSULATORS Original Filed March 17, 192 2 Sheets-Sheet l MI/ENTOR Irma ass.- Wm, awk A 727 aJfiorzze July 28, 1931. D. H. OSBORNE METHOD OF MANUFACTURING INSULATORS Original Filed March 17; 192 2 Sheets-Sheet 2 hrs w 0 4 7y r a v p KlQqOU Patented July 28, 1931 UNITED STATES PATENT OFFICE QSBOItNEQF IEFFERSONVIIJLE, PENNSYLVANIA, ASSIGNO'R TO ELEC 'TRIG SERVICE SUPPLIES COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A COR-.-

.- PORATION OF PENNSYLVANIA METHOD or MANUFACTURING ,INSULATORS Original application filed March 17, 1927, Serial No. 176,268. Divided and this application filed December 20; 1928. Serial No. 327,312.

This invention relates; to insulators and Y with regard to certain more specific features, to insulators used in connection wlth supports for electric lines. It relates also to the method of manufacturing insulators.

. This application is a'division of applica- 1 determined relationship by a mass of an imtionSerialNo.176,268, filed March 17, 1927,

which has become Patent 1,758,462.

'Amongthe several objects of the invention 7 may be noted the provision of an insulator comprising two'or more parts, held in a preproved' class of cement, having applied thereto" an improved method of setting, whereby a commercial degree of strength is rapidly attained after manufacture; the promg no substantial curing period; the provivlsion of an insulator ofthe class described which, in view of the methodemployed, can be'used soon after manufacturlng, requirsion of an insulator of the class described wherein the mass'of cement is used as a key,

after hardening thereof has taken place,

A rather than as a surface bonding material;

and the provision of an improved method of manufacturing insulators requiring a minimum amount of time and minimum cost but providing a better product.

out hereinafter. I V The invention accordingly comprises the elements and combination of elements, steps and sequence of steps features of construction, and'arrangements of part-which Wlll be exemplified in the structure hereinafter described, and the scope of the application Fig. 8 isa view similar to Fig. 1' showing a modified form; I

Fig. 4 is a view similar to Fig. 2 showing a part of the insulator illustrated in Fig. 3 5

7 Other objects f will be in part obvious and in part pointed 30- y Fig. 5 is a diagrammatic view illustrating the improved method of manufacturing;

Fig. 6 is a fragmentary diagrammatic view'illustrating a modified form of said' method; and

Fig. '7 is a diagrammatic view illustrating another modified form of said method' Corresponding reference charactersindicate corresponding parts throughout the several views of the drawings.

Insulators of the type to which this invention relates are composed of two or more parts which are connected together, usually by the use of Portland cement. Among the disadvantages attendant upon the use of Portland cement is the fact that it takes a relatively long time-to attain a commercial degree of strength. In the present invention, a method of manufacture and combination of materials is used which reduces this time required. An improved cement is used which provides a greater final commercial strength, and improved dielectric qualities. p

This invention also provides an insulator so constructed that its parts will be effectively secured'together and at the same time" soconstructed as to substantially eliminate the concentration of the strains arising from operating conditions and changes in tem'- perature. I

Referring now more particularly to the drawings, which clearly illustrate the pres ent improvements, there is illustrated at 1111- meral' 1 (Figs. 1 and 2) the center shell of an insulator 2, provided with a recess 3 for the reception of a supporting pin, while the numeral 5 indicates a top or cap provided witha central recess within which the upper end of the shell 1 is adapted to extend, that is. when the top and center shell are assembled.

The upper'end portion ofthe center shell" side and outside surfaces of the headportion V outermost girth3l of the head 19' whereby the members 19 'and2'3lniay be loosely tele- 1 V the shell and top.

together by means of a layer ofimprovedcement 13, which lies between the members and extends into and fills the rooves 7 and 9. This cement will be described more in detail hereinafter. my

It will now be noted that be'.ween the cement 13 and the adjacent surfaces of the center shelljand the top 5 respectively, there is a -l .ayer of compressible material of substantial thickness, which prevents the cement from bonding to the porcelain surfaces and acts to compensate for'any difference in the rate of expansion or contraction of the cement and of the porcelain, with changes in temperature, thus-avoiding the setting up of strains on the porcelain. It'will be also noted that the layers, of compressible material substant-ia lly preventconcentration of strains between the center shell and top under con ditions of service loading. Finally, it will be noted that thecenter shell and top are of fectively secured together bythe fact that the "cement is keyed into grooves 7 and 9 in It. is to beunderstood that this constructional portion of the invention is applicable in other forms, including added improvements. Anotherform is illustrated in Figs. 3 and 4x I V In said Figs. 3 and, numeral 15 illus trates an insulating member comprising a skirt, bell or disc shape 17 having suitable convolutions and a cup shaped head section 19. A blind recess 21 extends upwardly into thehead 19 from the. underside thereof.

- Y The insulator 15 is composed of porcelain or other suitable insulator material. The in- 19 are prepared so that the improved cement will not'bond to said surfaces directly. "The preparation of the s'urfacesisin the nature vof a smoothing operation and one. meansof accomplishing it is to glaze-the insulator. i A hardware cap, 23, composed preferably of metal, is adapted to slip over and loosely cooperate with saidhead 19 of the insulator.

;. This cap 23 is of suchdimensions that it hasaspaced relationship with respect to said head 19. Its lower end is formed as a head 25, from the outer edge of which head 25 there extends inwardly and downwardly a iconical portion 27. The innermost lip 29 of the conical portion 27 is adapted to clear the scoped with one another.

Theouter surface of the porcelain insuconical portions described. 7

is adapted to loosely receive in spaced relationship thereto, a suspension member 43 hav ng an upwardtapered portion 150f such diameter so as to slidably fit and clear said:

cylindrical portion 39. Suitable'grooves or V the 'lil le l may be formed in the cylindrical portion ofthe suspension. member;4:3., v

The loading surfaces of the engaging membersdescribed are coated with said yieldingmaterial used in the previously, described form and numbered 47 in Figs. .3 and, 4. After the surfaces in :question liavebeen coated, they are set intotherrelative positions illustrated in the drawings andat the same time layers of the improved cement (to be described) are interposed between the insulators and the suspension member and cap portions. 7 j

One mechanicaltheory of the device illustratedin Figs. 3 and is that the coating 4:7:- permits shrinkage of the cementwithout-inducing cracks, because the cement is not bonded. This means that ifcertain of the members joined are cooled suddenly, that the device may have relative contraction Without crushing the cement to causefailure. The

a mechanical loads are better distributed because surfacc regularities are compensated by the coating 47. Anothcrfeature isthatthe load-transmitting surfaces areangularly arranged in an inverse rmanner, whereby the masses'of cement therebetween function as keys to prevent separation of the surfaces. The angularity is attained by means 'ofthe The improved form of cement to 'beused comprises what is generally known as an aluminate cement, which comprises a mixture of calcium oxide, aluminum oxide and, iron oxide together with miscellaneous materials, mixed in suitable, proportions to form a h draul c cement.ada ated to bemixed with water and (if desiredlwith anaggregate, such as sand or other divided material. The advantage of this cementis that the abovenamed ingredients when mired'with water actually have a chemical action, as well as the ordinary-growth of crystals (the latter due to the Water of crystallization). i

The chemical action generates a certain amountof "heat as the cement sets. The improved 'J'manufacturingi process herein detempts;

scribed is; adaptedil) to supply to the ce- "ment the waterthat,itrequires for effective setting, and (2) to carry away this heat as the heat is generated. The cementthus attains a high degree ofstrength and does this comparatively rapidly. "The result is not a deleterious quick setting but a growthof strength within a shorter time. Nopextraneous heat is used. a V

The followingapp'roximate formula are given in order to show the distinct difference between Portland cement and an aluminate cement: I

Portland cement Aluminate cement Per cent Per cent SiO 22.0 A1 0 A12O3 6.5 F8203 F6 0 3.0 C510 40 CaO 63.0 Miscellaneous 5.0 M O 3.0'

S 3 1.5 V Impurities 1.0

' hardening is cludes means for prov ding water or crystal- As will be seen from the above, an aluminate cement is characterized by a high percentage of aluminum oX1de. ,As here1nbe 'fore indicated, the alummate cement is slow setting and quick hardening. Setting and hardening of cements are terms which should be distinguished, because setting refers to the loss of the adaptability to be molded and a subsequent phenomenon which represents increase in strength,

Ordinarily the heating action which takes ,place during the hardening of an aluminate cement drives off surface water, thereby reducingthe water of crystallization at said surface and causing crumbling. This invention is adapted, to provide water of'crystahlization as the heating proceeds.

Furthermore, this invention reduces the heating effect, whereby less original water is caused to be lost and a faster hardening rate attained. It has been found that a cooling process results in acfaster rate of hardening with a higher final strength.

Another advantage of aluminate cements over Portland cement-1s that they have much higher insulating properties. i

The lmproved manufacturing process inlization for the cement, after it is positioned in the insulators, and at the same time providing cooling means.

One form of the improved manufacturing "process is illustratedin Figure 5 in which achamber 49 is employed, said'chamber having a suitable charging door .51 and a rack 53 for supporting a quantity of insulators of the. class described. An inlet 55 is associated withsaid chamber 49. and an outlet 57, said inlet.

55 communicating with a humidifyi-ng system 58. By this means humidified air is blown in at the inlet 55 and passesthrough the ..chamber 49 and out of the outlet 57. By this porting a plurality of the insulators.

meansthe required "amount of moisture for" hydraulic action of the cement is introduced into the chamber; An ambient abnormally humidified atmosphere is maintained about the insulators.

Ths chamber and its contents are cooled by providing a jacket 59 therearound, communicating with an inlet 61 and an outlet 63, the

former being supplied with a fluid which has.

been artificially or otherwise cooled. The

fluid may comprise air, brine or other suitable" substance. I

The cooled substance circulates about the chamber 49 andleaves at the outlet 63. ,By

this cooling means heat may be carried off.

The cooling means will usually be artificial during hot weather. process is abnormal,that is, faster than would ordinarily obtain were the insulators main tained at the room temperature maintained where they'are dried.

The heater circulation and/or cooling: jacket may be omitted if desired, and the wa-\ ter spray delivered to a chamber in which the insulators are located,with a drain for removing water that collects on the floor of the chamber.

- The operation is as follows: I

The component parts of the insulators are assembled with the plastic aluminate cement therebetween and introduced into the cham' 'ber 49 while the cement is in its wet state.

The chamber 49 is closed and as the ordinary setting of the cement takes place, humidified air is forced into andthrough the chamber while it is cooled from the outside. Thus moisture for water of crystallization is provided and as the heat generates, due to set-- ting of the cement, said heat is carried away by means of the jacket 59. It is to be understood that auxiliary cooling coils may be placed directly between the insulators within the chamber, if desired. 7

In Fig. 6'is shown a slight modification in which a cold air connection 65 is made directly to the inside of the chamber 49. The same result as above described is accomplished, except that local direct cooling is had instead or" indirect cooling. 'The cold air exhausts from the opening 57 with the humidified air.

67. The valves 71, 73 are opened and the.

valve 75 closed. The position of the overflowis suchas to maintain the liquid level 76 In any case cooling.

in the container at an elevation submerge the insulators.

If desired, the water, instead of being circulated, may be charged into the container 67 up to a predetermined level and the supply" then cut off. This charge of Water will" abachieved and other advantageous results atsorb heat from thesetting cement and at the same time furnish the water of crystal-1i zation After each batch of insulators has set a suitable time, the water may be drained from the outlet and the insulators re moved, or the water may be permitted to cool and be again used.

' In View of the above, it will be seenthat the several objects of the invention are trained. Y "As many changes could be made in carrying out the above construction withoutdeparting from thescope of the invention, it is intended that all mattercontained inthe' above description orshown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

VV'hat claim and desire to protect by Letters Patent is= 1. The method of manufacturing insulators comprising assembling insulator components with wet cement, maintaining an ambient humidified atmosphere about the assembled components and simultaneously cooling them.

2. The method of ananufacturing insulatorscomprising assembling insulator components wlth wet cement, maintaining an ambient abnormally humidified atmosphere about the a'ssembledcomponents and simultaneously cooling them by abnormal means.

3. Themethod of manufacturing insulators comprising assembling insulator components with. wet cement, maintainingan ambient hquld about the assembled com-' ponents and cooling saidfluid.

4. The methodvof manufacturing insula tors comprlsing assembling insulator components with wet cement and maintaining for a timea cool ambient circulating liquid about the assembled components. v

'5. The m'ethod'of manufacturing insulators comprising assembling insulator com ponents with wet cement and maintaining a cool ambient liquid about the assembled com ponent-s.

6. The method of ponents with wet aluminate cement and maintamlng for a time a cool ambient liquid about the assembled components.

7. The method of manufacturing insulai tors comprising assembling insulator components with wet cement, mamtamingan ambient'humidlfied atmosphere about the as sembled components and locally cooling them.

'8. -Th e method of manufacturing insulais emme:

adapted to manufacturing insula I tors comprlslng assembling insulator comtors comprising holding at least two meat berstogether with cement and setting the cement in the presence of moisture while cooling the cement.

9. The method of manufacturing insula- 

